Hydrocarbon emission control of a hydrocarbon adsorber and converter under cold start of the gasoline engine

Abstract In this paper, a hydrocarbon (HC) adsorber and converter (HCAC) system is proposed for hydrocarbon emission control during cold start (Hydrocarbons are adsorbed in HC adsorber in the low temperature stage and HCs are released and converted by HC converter in the high temperature stage). Tandem HCAC scheme and dual layer scheme are proposed. To study the effect of the key structural parameters of HCAC on the performance of HC adsorption and conversion, the numerical simulation was carried out with propene as the probe. Dubinin-Astakhov model was used as the adsorption model, and fluent UDF function was used to compile the fitted D-A model for providing the adsorption source. The porosity of the porous zone, the length and diameter of the adsorber and converter of HCAC were studied. The calculation results show that the dual layer HCAC is the better scheme for the adsorption and conversion of HCs. The primary and secondary relationships of the three factors are porosity > length > diameter for adsorption performance and porosity > diameter > length for conversion efficiency. Orthogonal experiment analysis showed that the dual layer HCAC with porosity of 0.75, length of 150 mm and diameter of 150 mm had the best adsorption and conversion performance. The duration of adsorption efficiency over 50% can reach 102s, which is far enough for the light-off of converter, the conversion efficiency at the end of the cold start can reach 42%.